The object of this work is to give in the plainest possible manner all instructions, rules, and tables necessary for the location, construction, equipment, and management of railroads.
As a general thing, American engineers are not educated for their business; and when they do possess a knowledge of pure science, they are at a loss how to apply it.
The reader is presumed acquainted with the elements of arithmetic, geometry, algebra, and mechanics: being thus provided, he will, by a perusal of what follows, be enabled to correctly proportion bridges, of wood, stone, and iron: abutments, piers, retaining walls, superstructure, and locomotive engines; and to plan and lay out, execute, and estimate any description of work occurring upon railroads.
As the object has been more to be useful than original, the best engineering writers and experimenters have been consulted; among whom are,—Gauthey, Navier, Vieat, Tredgold, Barlow, Totten, Fairbairn, Hodgkinson, Clark, and Lardner. Also a great number of reports by American civil engineers upon railroad matters.
If assumptions take the place of demonstration, it will be on good authority. Readers will bear in mind that the work is a “handbook,” and not a “treatise.” It is intended more as an office companion than as a text-book for students. It will give in all cases the actual numerical result needed, whether it be the scantling of a bridge chord, the thickness of a wall, or the dimensions of a locomotive boiler.
In connection, it will be found convenient to use the works of Trautwine and Henck, on Field Work: of Lieutenant Smith, on Topography; Davies, on Surveying; and Gurley, on the Use of Instruments.
Any one wishing a complete treatise on the principles of bridge construction is referred to the excellent work of Hermann Haupt.
I take this opportunity of heartily thanking the engineers who in many ways have aided in making the work, as it is believed, of some worth.
| Page | ||
|---|---|---|
| Introduction | 1 | |
| CHAPTER I.— | Reconnoissance | 12 |
| II.— | Survey | 24 |
| III.— | Location | 41 |
| IV.— | Preliminary Operations | 55 |
| V.— | Laying out Work | 89 |
| VI.— | Earthwork | 97 |
| VII.— | Rockwork | 115 |
| VIII.— | Wooden Bridging | 122 |
| IX.— | Iron Bridging | 192 |
| X.— | Stone Bridging | 233 |
| XI.— | Masonry | 248 |
| XII.— | Foundations | 261 |
| XIII.— | Superstructure | 272 |
| XIV.— | Equipment | 302 |
| XV.— | Stations | 403 |
| XVI.— | Management | 413 |
| Appendix | 459 |
| INTRODUCTION. | |
| PAGE | |
|---|---|
| Rise and progress of railroads | 1 |
| Influence of railroads | 3 |
| Safety of railroad travelling | 5 |
| Preliminary operations | 5 |
| Mechanical principles of locomotion | 6 |
| Determination of character of road | 7 |
| Gauge | 8 |
| General establishment of route | 10 |
| CHAPTER I. | |
| RECONNOISSANCE. | |
| General topography | 12 |
| Barometrical levelling | 18 |
| CHAPTER II. | |
| SURVEY. | |
| Topographical sketching | 24 |
| General establishment of grades | 32 |
| Equating for grades | 34 |
| Comparison of surveyed lines | 39 |
| CHAPTER III. | |
| LOCATION. | |
| Alignment | 41 |
| Final adjustment of grades | 46 |
| Comparison of located lines | 47 |
| CHAPTER IV. | |
| PRELIMINARY OPERATIONS. | |
| Specification | 55 |
| Contract | 81 |
| Solicit | 84 |
| Bid | 85 |
| Comparison of bids | 87 |
| CHAPTER V. | |
| LAYING OUT WORK. | |
| Slopes | 89 |
| Culverts | 90 |
| Masonry | 91 |
| Tunnels | 95 |
| CHAPTER VI. | |
| EARTHWORK. | |
| Form of railroad sections | 97 |
| Excavation and embankment | 104 |
| Transport of material | 106 |
| Average haul | 106 |
| Drainage | 109 |
| Method of conducting construction operations | 111 |
| CHAPTER VII. | |
| ROCKWORK. | |
| Rock excavation | 115 |
| Blasting and quarrying | 115–117 |
| Tunnelling | 118 |
| CHAPTER VIII. | |
| WOODEN BRIDGING. | |
| Of the forces at work in bridges | 122 |
| Extension | 123 |
| Compression | 123 |
| Cross strain | 124 |
| Detrusion | 126 |
| Strength of materials | 126 |
| Rules for practice | 131 |
| Of the truss | 139 |
| Of the arch | 169 |
| Of the road-way | 174 |
| Lateral bracing | 175 |
| Pile bridging | 178 |
| Trestling | 180 |
| Draw bridges | 181 |
| Centres | 182 |
| CHAPTER IX. | |
| IRON BRIDGES. | |
| Nature and strength of iron | 192 |
| Classification of iron bridges | 194 |
| Iron truss frames | 195 |
| Suspension bridges | 203 |
| Boiler plate bridges | 223 |
| CHAPTER X. | |
| STONE BRIDGING. | |
| Of the water-way | 233 |
| Form of the arch | 236 |
| Thickness of voussoirs | 238 |
| Form and thickness of abutments | 239 |
| Form and dimensions of piers | 245 |
| CHAPTER XI. | |
| MASONRY. | |
| Stone | 248 |
| Cements, mortars, and concretes | 249 |
| Construction of arches, wings, and parapet | 253 |
| Culverts and drains | 255 |
| Retaining walls | 256 |
| CHAPTER XII. | |
| FOUNDATIONS. | |
| Pile driving, common system | 262 |
| Mitchell’s screw pile | 266 |
| Potts’s atmospheric system | 266 |
| Coffer-dam | 267 |
| Caisson | 269 |
| CHAPTER XIII. | |
| SUPERSTRUCTURE. | |
| Timber work | 273 |
| Rail section | 276 |
| Chairs and joints | 282 |
| Frogs | 290 |
| Switches | 294 |
| Sidings and crossings | 298 |
| Elevation of exterior rail | 298 |
| CHAPTER XIV. | |
| EQUIPMENT. | |
| PART I. LOCOMOTIVES. | |
| Introduction | 302 |
| Birth and growth of the locomotive | 302 |
| The English locomotive of 1850 | 304 |
| The American locomotive of 1855 | 305 |
| General description | 306 |
| Mechanical and physical principles | 312 |
| Resistance to the motion of trains | 312 |
| Traction and adhesion | 316 |
| Fuel | 317 |
| Generation of steam | 330 |
| Application of steam | 336 |
| Boiler proportions and dimensions | 340 |
| Rules and tables for practice | 354 |
| Adaptation of locomotives to the movement of trains | 360 |
| Classification of engines | 371 |
| PART SECOND. | |
| CARS. | |
| Wheels and axles | 396 |
| Classification of cars | 400 |
| Retarding of trains | 401 |
| CHAPTER XV. | |
| STATIONS. | |
| Classification of buildings | 403 |
| Location of buildings | 403 |
| Terminal passenger house | 403 |
| Terminal freight house | 405 |
| Engine house and appurtenances | 405 |
| Way passenger and freight house | 407 |
| Wood shed and tank | 407 |
| CHAPTER XVI. | |
| MANAGEMENT. | |
| Organization of employees | 413 |
| Duties of employees | 415 |
| Number of trains to be used | 418 |
| Amount of service of engines | 418 |
| Expenses, receipts, profits | 420 |
| Express trains | 428 |
| Comparative cost of working heavy and light trains | 434 |
| Branch roads | 436 |
| Reproduction of road and of stock | 437 |
| Working railroads by contract | 439 |
| Classification of freight | 439 |
| Time tables | 443 |
| Locomotive registers | 444 |
| Electric telegraph | 454 |
| New York and Erie Railroad | 456 |
| APPENDIX. | |
| A.—Decimal Arithmetic | 459 |
| B.—Algebraic formulæ | 461 |
| C.—Weights and measures | 464 |
| D.—Value of the Birmingham gauges | 465 |
| E.—Locomotive boilers | 466 |
| F.—Effect of grades on the cost of working | 468 |
| G.—Form for a locomotive specification | 471 |
| H.—Relative cost of transport by railroad and by stage | 476 |
| I.—Form for experimental trips with locomotives | 478 |
| K.—Proper weight for locomotives | 479 |
The reader is particularly requested to apply the following errata before perusing the work. They are partly mistakes in printing, and partly errors in the original MS. The only excuse the writer can offer for the number is, that, being engaged in Missouri, while his publishers were in Boston, he has been prevented from seeing a single proof-sheet in time for its correction.
Page 5, line 7, for “499.999,” read “499,999.”
— 5, l. 9, for “49.999,” read “49,999.”
— 10, l. 1, for “can be,” read “can never be.”
— 12 to 23, headings, for “reconnoitre,” read “reconnoissance.”
— 18, l. 24, for “36.9,” read “36.8.”
— 19, l. 6, for “table B,” read “table D.”
— 24, l. 1, for “any thing,” read “every thing.”
— 25, l. 17, for “horizontal line m m m,” read “line 1, 2, 3,” etc.
— 26, l. 2, for “land,” read “level.”
— 27, l. 1, for “at the place,” read “at the right place.”
— 28, l. 29, for “reconnoitre,” read “reconnoissance.”
— 30, l. 3, for “A c d B,” read “A C D B.”
— 32, l. 2, the point m in the cut, is one whole division above C; it should be only three fourths of a division.
— 38, l. 10 from bottom, for “276,” read “268.”
— 39, l. 10 from bottom, for “142.13,” read “143.13”; and last line, for “58.46,” read “48.46.”
— 40, l. 7, for “10310,667,” read “10,277,333.”
— 42, l. 9, for “Thus,” read “These.”
— 42, l. 8 from bottom, for “2°.81 or 2° 48′.6” read “2°.86 or 2°.51.6.”
— 43, l. 27, for “Hencke,” read “Henck.”
— 47, 48, 49, for “McCullum,” read “McCallum.”
— 47, l. 18, for “distance,” read “resistance.”
— 48, l. 6, for “infringing,” read “impinging”; line 9, for “slacking,” read “shackling”; l. 8 from bottom, for “increased,” read “increases.”
— 50, l. 17, for “110 + 15.60,” read “110 + 15.62.”
— 52, l. 15, for “45.59,” read “45.49”; also l. 17, for “1132,” read “11.32.”
— 58, l. 10, for “of size,” read “and size.”
— 58, l. 5 from bottom, for “one cent,” read “
100 of a cent.”
— 61, l. 3, for “are necessary,” read “are not necessary.”
— 63, l. 28, for “stretches,” read “stretchers.”
— 65, l. 15, for “spanded,” read “spandrel.”
— 71, l. 6 from bottom, for “left,” read “let.”
— 73, l. 19, for “chains,” read “chairs.”
— 74, l. 5, for “across ties,” read “on cross-ties.”
— 74, l. 12, for “28 inches,” read “27 inches.”
— 75, l. 18, for “land,” read “haul.”
— 76, l. 8, for “top,” read “bottom,” and for “charred when,” read “charred where.”
— 76, l. 11, for “twopenny,” read “tenpenny.”
— 78, l. 1 and 2, for “base,” read “basis.”
— 84, l. 13, for “as,” read “or.”
— 89, l. 6, for “Whenever,” read “Wherever”; l. 12, for “Letting,” read “Setting.”
— 90, l. 4, for “cost,” read “cut.”
— 93, l. 6, for “37 and 38,” read “36 and 37.”
— 95, l. 1, for “beach,” read “bench”; l. 3, for “to so,” read “so to”; l. 13, for “b being 10 ft. back of 2 is ... 100.00,” read “b being 10 ft. back of 2 is 0.1 ft. higher than 2, or ... 100.10.”
— 102, l. 1, head of middle col., for “Slopes 1¼,” read “Slopes 1½.”
— 103, l. 4 from bottom, for “and ten feet,” read “and one end ten feet.”
— 104, l. 9, for “any,” read “very.”
— 108, l. 9, for “Elwood,” read “Ellwood.”
— 115, l. 5, for “a loam,” read “a berm”; l. 16, for “a rent,” read “a vent.”
— 117, l. 7, for “volcanic,” read “voltaic.”
— 117, l. 9, for “Round Drum,” read “Round Down.”
— 117, l. 18, for “Col. Puseling,” read “Col. Pasley.”
— 118, l. 2, for “Maillefaut,” read “Maillefert.”
— 118, l. 16, for “insert,” read “invert.”
— 118, l. 25, for “quointed,” read “grouted.”
— 119, l. 30, for “furnished,” read “finished.”
— 120, Table, for “Nochistingo,” read “Nochistongo”; for “Supperton,” read “Sapperton”; and for “Black Rock, W. S.” read “Black Rock, U. S.”
— 121, l. 19, for “Belchingly,” read “Blechingly.”
— 125, in table at bottom, for “90
69,” read “90
66,” and for “140, 20
140, 20
160 or 0.13,” read “111, 20
111, 20
131, or 0.15.”
— 126, l. 1, for “extensive,” read “extensile.”
— 127, l. 10, for “67,200,” read “65,251.”
— 127, l. 26, for “Hodgekinson,” read “Hodgkinson.”
— 128, l. 4, for “12000,” read “11000.”
— 128, l. 15 and 22, for “Hodgekinson,” read “Hodgkinson.”
— 129, l. 5, for “12000,” read “11000.”
— 129, l. 2 from bottom, for “Sun Wood,” read “Ironwood.”
— 130, l. 7, for “WL2 = 4Sbd2,” read “WL = 4Sbd2.”
— 131, l. 9, for “wood 143,” read “wood 133.”
— 134, in art. 164, for “700,” read “952.”
— 136, for example there given, place the following:—
| Span | 30 feet, | Whence— | |
| Length | 34 feet, | Length | 34 feet, |
| Load | 10 tons at centre. | Span | 30 feet, |
| Depth | 25½ inches, | ||
| Lower flange | 32.58 square inches, | ||
| Upper flange | 5.34 square inches, |
and 32.58
6.1 = 5.34.
— 141, last line, Fig. 63 A was omitted; it is the same as fig. 102, page 200, inverted.
— 142, last line, for “span,” read “spans.”
— 146, head of col. 7, for “Top Washer,” read “Thickness of Washer.”
— 150, after line 9, Figs. 67 D and 67 E (page 153) should be inserted.
— 151, l. 3, for “W = 2249,” etc., read “W = 2240,” etc.
— 151, l. 18, for “opposite to 31,416, is the diam. 1⅝,” read “opposite to 41,415, is the diam. 1⅞.”
— 151, l. 19, for “1⅝,” read “1⅞.”
— 154, last line, for “tubular,” read “tabular.”
— 156, l. 4 from bottom, for “washer band,” read “washer used.”
— 164, l. 10 to 14, inclusive. The first number of ratios should be 20 instead of 15.
— 166, l. 11, for “69 B,” read “69 A.”
— 171, head of col. 5 of table, for “Rod of Arch,” read “Rad. of Arch.”
— 173, l. 25, for “ability,” read “stability.”
— 173, l. 32, for “Whence,” read “Where.”
— 175, l. 8, for “triangular,” read “diagonal.”
— 178, l. 3, for “article,” read “outside.”
— 184, l. 4 from bottom, for “barriers,” read “voussoirs.”
— 187, fig. 96 is upside down; also, fig. 97, page 188, and fig. 98, page 189.
— 193, l. 4, col. 3 of table, for “.00000675,” read “.00000685”; also, l. 16, col. 5, for “straining,” read “shearing”; l. 7 from bottom, for “15,000,” read “18,000;” and l. 6 from bottom, for “75,000,” read “105,000.”
— 199, l. 7 from bottom, for “20,132,” read “20,312.”
— 200, l. 4, for “A C,” read “A G”; and l. 6, for “that on A R,” read “that on A K.”
— 202, l. 7, for “on page 193,” read “on page 138.”
— 204, l. 5 from bottom, for “varied line,” read “versed sine.”
— 207, l. 5 and 6, for “F G, G E, in place of E F, E C,” read “G L, G E, in place of F L, F C.”
— 210, in place of “f′ = πF
4ph,” put “D = √¾[V2 – d2] – √¾[l2 – d2].
— 211, omit the 6th and 7th lines, and in place of formula there given, use that on page 210, (as corrected,) V being the length of semi-curve as elongated by heat instead of by tension; the elongations, both by heat and tension, being found by table on page 193.
— 212, l. 2, for “510.69,” read “510.80,” which result, of course, runs through the whole example.
— 213 and 214. The remarks under “Anchoring Masonry,” are evidently wrong throughout: 1st, the whole tension should be divided by two, instead of four, as half of the whole tension acts at each point of suspension; 2d, no reduction should be made for the direction of the pulling force. One half of the tension is 3,321,250 lbs.; which is resisted by a column of masonry of 3,321,250
160 = 20,758 cubic feet, or 20 × 20 × 52 feet, or by a mass 15 × 15 × 91 feet.
— 214, l. 6, for “561,527,” read “562,542.”
— 215, l. 14 from bottom, for “STIFFENING TOWERS,” read “STIFFENING TRUSSES.”
— 225, l. 14, for “194,” read “193.”
— 226, l. 3, for “see page 128,” read “see page 193.”
— 227, l. 4, for “detensional,” read “detrusional.”
— 228, in place of equations at l. 16, put “R × a = R′ × (2 d × t)”,
— 229, in art. 242, the strengths of “wrought iron,” have been taken for those of “boiler plate”; that is, 11,000 for 7,500, and 15,000 for 12,740, which is wrong.
— 231, l. 21, for “chopped,” read “dropped.”
— 234, l. 4, for “joint,” read “just.”
— 235, l. 14, for “0.016 feet,” read “0.047 feet.”
— 236, l. 9, for “care,” read “ease.”
— 237, l. 3 from bottom, for “representing,” read “separating.”
— 241, l. 2, for “localities,” read “locality.”
— 242, l. 7, omit “and c e, the parapets.”
— 243, l. 9, for “embankment,” read “abutment.”
— 244, l. 9, for “is thus,” read “is found thus.”
— 245, l. 17, for “latter,” read “batter.”
— 249, l. 23, for “common hydraulic,” read “common mortar, hydraulic.”
— 249, l. 27, for “argyle magnesia,” read “argil, magnesia.”
— 251, l. 16, for “7½ to 2,” read “1½ to 2.”
— 254, last l., for “corners,” read “courses.”
— 256, l. 13, for “formed,” read “found.”
— 258, art. 276, in place of “20
2 × 15 × 1 × 100 × 20
3,” put “20 × 15 × 1 × 100 × 2 × 20
3,” where 2 represents the ratio between Ca 6, and 6–2; thus, 20 × 15 × 1 × 100 × 6.6
12 × 20
3 = 111,111, for the overthrowing force in place of 100,000. The overthrowing force is thus large, because the maximum weight of earth has been assumed to press against the wall with its whole force, no allowance being made for friction. In practice, 4
10 of the height has been found amply thick for walls retaining ordinary earth.
— 262, last l. but one, for “superstratum,” read “substratum.”
— 264, in example, l. 5, for “26,667,” read “48,000.”
— 266, l. 25, for “Godwin,” read “Goodwin.”
— 266, l. 26, for “There, sands,” read “These sands.”
— 267, l. 22, for “bottom,” read “proper level.”
— 281, l. 4 from bottom, for “curve,” read “cone.”
— 282, l. 20, for “Daniel,” read “David.”
— 282, l. 4 from bottom, for “cup,” read “cap.”
— 284, l. 10, and 285, l. 8, for “compressed rails,” read “compound rails.”
— 285, l. 5, for “extension,” read “extensile.”
— 289, invert col. 1 of table, so that it shall read—
— 289, last l., for “levelled,” read “bevelled.”
— 291, last l., for “a c, 4.8,” read “a c, L 8.”
— 292, l. 9, for “e h and d k,” read “e L and d k”; same p. l. 6 from bottom, for “a, 9 is three, etc.” read “a b is three,” etc.
— 293, l. 6 and 7, for “i g, e h, b b, 8, 9, A s 79,” read “i g, e h, a c, b c.”
— 296, l. 14, for “R2 – R – 82,” read “R2 – R – g2.”
— 303, art. 299, for “M. Leguire,” read “M. Seguin.”
— 306, l. 2, for “R. R. & G.,” read “R. K. and G.”
— 314, l. 2, for “D. R. Clark,” read “D. K. Clark.”
— 320, l. 1, for “Railroad, three pounds (Pennsylvania),” read “Railroad (Pennsylvania), three pounds.”
— 320, l. 7, for “coal,” read “coke.”
— 331, near bottom, for “The area is, therefore,
| Sides, twice length, etc., | read | “Sides, twice length by height, etc., |
| Back, twice height, etc., | Back, height by width, etc., | |
| Front, twice height, etc., | Front, height by width, etc., | |
| Top, twice length, etc.,” | Top, length by width, etc.” |
— 334, l. 15, for “44.7 lbs.,” read “14.7 lbs.”
— 335, l. 7, for “Railway Mechanics,” read “Railway Machinery.”
— 335, l. 10, for “two velocities,” read “low velocities.”
— 336, last l., for “entering part,” read “entering port.”
— 341, l. 11, for “properties,” read “proportions.”
— 341, last l., for “Nollan,” read “Nollau.”
— 346, l. 17, for “part,” read “port,” and for “construction,” read “contraction.”
— 355, l. 7, for “6300,” read “5170”; and l. 9, for “16,905,” read “15,775.”
— 363, l. 17, for “44 × 2 = 80,” read “44 × 2 = 88.”
— 363, l. 18, for “54½ × 3 = 103½,” read “54½ × 3 = 163½.”
— 367, l. 16, for “15.0
10,” read “15.0
16,”
— 368, l. 15, for “u = 135,” read “n = 135,” etc.
— 370, l. 7, for “feet,” read “per cent.”
— 376, for “19090,” read “19050.”
— 384, in last part of example, for “5280
4½ × 3.1416 × 4 = 37300,” read “25 × 5280
4 × 3.1416 × 4 = 37348.”
— 421, bottom line, for “decision,” read “division.”
— 423 and 424, in table, for “count,” read “cost.”
— 427, l. 32, for “which,” read “we.”
— 428, l. 4, transpose “Dr. Lardner, (1850,)” to the end of line 3.
— 443, l. 28, for “valuation,” read “solution.”
— 446, l. 11, for “attained,” read “obtained.”
— 459, l. 20, for “Hectametre,” read “Hectometre.”
— 459, l. 21, for “Ridometre,” read “Kilometre.”
— 461, l. 7, for “less than a, or o,” read “less a, or 0.”
— 468, l. 30, for “fractions,” read “functions.”
— 474, l. 18, for “Balbett,” read “Babbitt.”
— 479, l. 10, for “one sixth, with much less,” read “one sixth; with sand, much less.”
“They build not merely roads of earth and stone, as of old, but they build iron roads: and not content with horses of flesh, they are building horses of iron, such as never faint nor lose their breath.”—Dr. Bushnell.
1. In 1825, the Stockton and Darlington Railroad (England), was opened.
In 1827, the Quincy (of Massachusetts), and Mauch-Chunk (Pennsylvania), were completed.
In 1829, the Liverpool and Manchester road, (England), was finished.
In 1833, a road was opened from Charleston, (South Carolina), to Augusta (Georgia).
In 1840, Belgium opened 190 miles of railroad.
In 1843, the railroad from Paris to Rouen (France), was completed.
In 1844, Belgium finished her system of 347 miles.
In 1846, Russia opened a railroad from the Wolga to the Don.
In 1847, Germany had in operation 2,828 miles.
In 1852, the Moscow and St. Petersburg road was finished.
2. In 1856, the United States of America had in operation 23,000 miles, and in progress 17,000 miles; employing 6,000 locomotive engines, 10,000 passenger and 70,000 freight cars; costing in all about 750,000,000 of dollars; running annually 114,000,000 miles, and transporting 123½ millions of passengers, and 30 millions of tons of freight per annum; performing a passenger mileage of 4,750,000,000, and a freight mileage of 3,000,000,000.
3. By mileage is meant the product of miles run, by tons or by passengers carried. Thus, 500 persons carried 100 miles, and 750 persons carried 75 miles, give a passenger mileage of
4. The rate of progress in the United States has been as follows:—
| In 1828, | there were 3 miles. |
| In 1830, | 41 miles. |
| In 1840, | 2,167 miles. |
| In 1850, | 7,355 miles. |
| In 1856, | 23,242 miles. |
At the present time, January 1, 1857, there is probably, in round numbers, 25,000 miles of completed road, or enough to extend entirely around the world. As regards the ratio of completed road to population, and as regards the actual length of railroad in operation, the United States stand before any other country.
5. The effect of a judicious system of railroads upon any community is to increase consumption and to stimulate the production of agricultural products; to distribute more generally the population, to cause a balance between supply and demand, and to increase both the amount and safety of travelling. It is stated that within two years after the opening of the New York and Erie Railroad, it was carrying more agricultural produce than the entire quantity which had been raised throughout the tributary country before the road was built.
6. The following table, cut from a Chicago paper, shows the effect of railroad transport upon the cost of grain in that market:—
| Wheat. | Corn. | |||
|---|---|---|---|---|
| By R. R. | By Wagon. | By R. R. | By Wagon. | |
| At market, | $49.50 | $49.50 | $25.60 | $25.60 |
| 10 miles, | 49.25 | 48.00 | 24.25 | 23.26 |
| 50 miles, | 48.75 | 42.00 | 24.00 | 17.25 |
| 100 miles, | 48.00 | 34.50 | 23.25 | 9.75 |
| 150 miles, | 47.25 | 27.00 | 22.50 | 2.25 |
| 200 miles, | 46.50 | 19.50 | 21.75 | 0.00 |
| 250 miles, | 45.75 | 12.00 | 21.00 | 0.00 |
| 300 miles, | 45.00 | 4.50 | 20.25 | 0.00 |
| 330 miles, | 44.55 | 0.00 | 19.80 | 0.00 |
Thus a ton of corn carried two hundred miles, costs, per wagon transport, more than it brings at market; while moved by railroad, it is worth $21.75 per ton. Also wheat will not bear wagon transport of three hundred and thirty miles; while moved that distance by railroad it is worth $44.55 per ton.
7. By railroads, large cities are supplied with fresh meats and vegetables, butter, eggs, and milk. An unhealthy increase of density of population is prevented, by enabling business men to live five, ten, or fifteen miles away from the city and yet do business therein. The amount of this diffusion is as the square of the speed of transport. If a person walks four miles per hour, and supposing one hour allowed for passing from the house to the place of business, he cannot live at a greater distance than four miles from his work. The area, therefore, which may be lived in, is the circle of which the radius is four, the diameter eight, and the area fifty and one quarter square miles. If by horse one can go eight miles per hour, the diameter becomes sixteen miles, and area two hundred and one square miles; and, if by railroad he moves thirty miles per hour, the diameter becomes sixty miles, and the area 2,827 square miles. The effect of such diffusion is plainly seen about Boston, (Massachusetts). People who in 1830 were mostly confined to the city, now live in Dorchester, Milton, Dedham, Roxbury, Brookline, Brighton, Cambridge, Charlestown, Somerville, Chelsea, Lynn, and Salem; places distant from two to thirteen miles.
8. In railroads, as in other labor saving (and labor producing) machines, the innovation has been loudly decried. But though it does render some classes of labor useless, and throw out of employment some persons, it creates new labor far more than the old, and gives much more than it takes away. Twenty years of experience shows that the diminished cost of transport by railroad invariably augments the amount of commerce transacted, and in a much larger ratio than the reduction of cost. It is estimated by Dr. Lardner, that 300,000 horses working daily in stages would be required to perform the passenger traffic alone, which took place in England during the year 1848. It is concluded, also, from reliable returns, that could the whole number of passengers carried by railroad, have been transported by stage, the excess of cost by that method above that by railroad would have been $40,000,000.
9. If we know that in a given time the whole distance travelled by passengers was 500,000 miles, and that in such time there occurred one fatal accident, it follows that when a person travels one mile, the chances are 499,999 against one of losing life. If he travel ten miles, the chances are 49,999 against one, or ten times as many of meeting with loss of life; and generally the chances of accident are as the distance travelled. In 1855, the whole number of miles run by passengers in the United States was, in round numbers, 4,750,000,000, while there were killed one hundred and sixteen; or one in every 41,000,000, very nearly. (The ratio in England is one in every 65,000,000.) Now if for each 400,000 miles travelled by stage passengers, (a distance equal to sixteen times round the world,) one passenger was killed, and if the whole railroad mileage could be worked by stages, there would be annually 11,875 lives lost; or one hundred times the number annually lost by railroad. Thus it would be one hundred times safer to travel by railroad than by stage. The danger of steamboat travelling is far greater than by stage.
10. The first step to be taken in starting a railroad enterprise, is the choice of a board of directors (provisional), whose duty is to find all that can be known of the commercial, financial, and agricultural nature of the country to be traversed. To determine as near as possible its ability to build and support a road; and to obtain the necessary legislative enactments.
11. The determination of the increase of traffic which the road may be expected to excite, is a difficult matter. There can be few rules given for proceeding in such an inquiry. It seems very easy to prove by what roads have done, that any project will be profitable.
An abstract of a report lately published, tries to prove that a road will pay forty-five and one half per cent. net; the working expenses being assumed at only thirteen and one half per cent. of the gross receipts. The error here lies in assuming the working expenses too low, as few roads in the country have been worked for less than forty per cent.; a more common ratio being fifty one-hundredths of the gross receipts.
Not one half of railroads are built for the original estimate. In few cases has sufficient allowance been made for the sacrifice undergone in negotiating the companies’ securities. All general instructions that can be given relating to the determination of prospective profits, are, to keep the estimate of constructing and working expenses high, and that of the assumed traffic low; not so low, however, as to require a too lightly built road.
12. The superiority which the modern railroad possesses over the common, McAdam, plank, or turnpike-road, consists, first, in the reduction of the resistance to motion, and second, in the application of the locomotive steam-engine.
13. The effect of grades of a given incline upon a railroad is relatively more than upon common roads; for as the absolute resistance on a level decreases, the relative resistance of grades augments: whence to obtain the full benefit of the system, we must reduce much more the grades and curvature upon a railroad, than on a common road. For example, if the resistance to moving one ton upon a level upon a railroad was ten pounds, and upon a common road forty pounds, where a twenty-three feet grade would be admissible upon the former, we might use an incline of ninety-three feet per mile upon the latter.
14. The resistance to the motion of railroad trains increases rapidly with the speed;[1] whence the grades of a passenger road where a high average speed is used, may be steeper than those of a road doing a freight business chiefly.
1.See chapter XIV.
15. Upon a correct idea of what the road ought to be, depends in a great degree its success. The amount of capital expended upon the reduction of the natural surface, depends upon the expected amount of traffic. The traffic remaining the same, the greater the capital expended in reducing grades and curvature, the less will be the working expense; and the less the construction capital, the greater that for maintenance. The limit of expenditure must be such as to render the sum of construction and maintaining capital a minimum.
The bad effect of grades upon the cost of maintaining and of working railroads, is not so great as many suppose. Of the whole cost of working, only about forty per cent. can be charged to locomotive power; and of this, not more than sixty-two per cent. is effected by grades.[2]
2.See appendix F.
16. The degree of curvature to be admitted upon any road depends somewhat upon the speeds at which trains are to be run. The larger the radius of curvature, the greater may be the speed; at the same time the elevation of the exterior rail upon curves may be less, and therefore more adapted to freight trains. High rates of speed are considered upon some competing roads necessary; but are, even in such cases, necessary evils. The wear of cars and of engines, of permanent way and of bridges, increase in a rapid ratio with the velocity. The maximum speed for freight trains should never exceed fifteen miles per hour, or for passenger trains from twenty to twenty-five miles per hour.[3]
3.See chapter XVI.
17. The agricultural nature of the country and its commercial position, will determine the nature of the traffic, whether passenger or freight, and also the amount. The amount and nature of the traffic will limit the curvature, and will partially determine the arrangement of grades.
18. The question of broad and narrow gauge has led to much discussion, and both plans claim among their advocates some of the best engineers. The narrow gauge (American and English,) is four feet eight and one half inches (from inside to inside of rail). The maximum adopted, is (the Great Western of England) seven feet. The American maximum (New York and Erie, and Ohio and Mississippi) is six feet. There is also in America four feet ten inches, five feet, and five feet six inches. The advantage of the broad gauge for a road doing an extensive business, is the increased stowage room in freight cars, thus rendering admissible shorter trains; by which the locomotive power is more directly applied on curves. More comfortable passenger cars, (the same length of car of course accommodates the same number of passengers). The disadvantages of a wide gauge are, increased expense of cutting, embanking, bridging, and masonry; increased expense of engines, cars, rails, sleepers, and all machinery; more wear and tear upon curves, by reason of greater difference between the lengths of inner and outer rails, and increased atmospheric resistance to fast trains, from increased bulk.
19. The general conclusion arrived at by a commission appointed by the Great Western Railway Company, (England,) consisting of Messrs. Nicholas Wood, J. K. Brunel, and John Hawkshaw, was, that four feet, eight and one half inches was rather narrow, but still enough for a certain class of roads; that two or three inches made no material difference; that seven feet was too wide for any road; that the weight of the broad gauge engine, compared with the small increase of power, was a serious evil; that engines could be run with perfect safety upon the narrow gauge at any speed from thirty to sixty miles per hour, and that no more had been attained upon the broad; that rolling friction was less upon the broad, owing to the increased diameter of wheels, but that friction from curves and atmospheric resistance was greater.
20. D. K. Clark, in “Railway Machinery,” p. 300, 301, makes the resistance as deduced from experiments made upon both the four feet, eight and one half inches, and the seven feet gauge, considerably greater upon the former than on the latter; but as the narrow gauge trials were made upon a curved road, with rails in a bad state, in average weather, while those upon the broad were made in good weather, upon a good and straight line, he leaves the gauge question open, and uses the same formula for all widths.
21. Want of increased power, can be an apology for increased gauge, until the capacity of the narrow gauge has been filled. The strongest engines in the world are upon the four feet, eight and one half inch gauge. No engines in America surpass or compare for absolute strength, with those upon the Baltimore and Ohio Railroad. The most powerful passenger engine ever built for high speeds, is Crampton’s engine “Liverpool,” (London and North-western Railroad, England,) gauge four feet, eight and one half inches.
22. The straight and level line connecting any two points, is of course the best for the completed road; but this is seldom practicable. Way towns must be accommodated to a certain extent; but the main line should not be lengthened on that account, unless the traffic and capital furnished by such town is not only sufficient to pay for the construction and maintenance of the extra length, but also to carry the entire through traffic over such increased distance. If the town is unable to support such a burden, it may be able to build and maintain a branch.
23. Routes placed upon the immediate bank of a large stream, are generally crossed by a great number of deep gorges, which serve to drain the side lands.
24. Routes placed upon sloping land, when the axis of the road and the natural descent are at right angles to each other, are more subject to slides than when placed upon plateaus or “bottoms.”
25. Lines crossing the dividing ridges of separate waters, rise and fall a great deal; thus rendering necessary a strong motive power to work the road. Such roads are the Western of Massachusetts, passing from the valley of the Connecticut at Springfield, to the Hudson River valley at Greenbush. Also those roads crossing the Alleghanies. And such will be the Pacific road, crossing first the Rocky Mountains to the Great Basin, and second, the Sierra Nevada into the Sacramento valley.
26. The object of the reconnoitre is to find approximately the place for the road, (i. e. within half of a mile,) to find the general form of the country, and to choose that part which with reference to the expected traffic, shall give the best gradients; to determine the elevations of summits upon competing routes; and, in fine, to prepare the way for the survey.
27. The general topography of a country may be ascertained by reference to State maps, where such exist, and when not, by riding over the district. The direction and size of watercourses, will show at once the position of summits.
Fig. 1.
28. Water flowing as in fig. 1, indicates a fall from B to E; and also traverse slopes from a a and c c to d d.
Fig. 2.
29. Fig. 2 shows a broken ridge a a a from which the water flows in both directions; and in general, the sources of streams point towards the higher lands.
Fig. 3.
30. If it be required to join the points A and D by railroad, (fig. 3.) it may be better to pass at once from A through B and C, than to go by the streams F E, F′ E′. By the latter route the road would ascend all of the way from A to E; and descend from E′ to D. By the first if it requires steep gradients to rise from A to B, and to fall from C to D, still if the section B C is a plateau, and if the rise between A and B and A and E is the same, by grouping the grades at B and C we may so adapt the motive power, as to take the same train from A to D without breaking. The general arrangement of grades by the line A B C D is then as fig. 4; and A F E E′ F′ D, as in fig. 5. The saving in this case is by length, as the same amount of power is required to overcome a given ascent.
Fig. 4.
Fig. 5.
31. Valleys generally rise much faster near their source, than at any point lower down; also the width increases as we approach the debouch. Fig. 6 shows the cross sections of a valley from its source to the mouth.
Fig. 6.
32. In the case of parallel valleys running in the same direction, the form will be as in fig 7. Let 1 2, 1 2, etc., represent a datum level, or a horizontal plane passing through the lowest point. The line a b, shows the height of the bottom at B; c d that at D, e f that at E, and g h that at C. The broken lines i, k, l, m, n, show the general form of the land. Now by the route m m m m, from A to F, we have the profile m m m m, fig. 8, by n n n n, the profile n n n n, and by o o o, the profile o o o.
Fig. 7.
Fig. 8.
Fig. 9.
33. In the case of parallel valleys running in opposite directions, as in fig. 9, we have the form there shown; and the profiles corresponding to the several lines are shown in fig. 10. As we should always adopt the line giving the least rise and fall, other things being equal, it is plain which line on the plan we must follow.
Fig. 10.
34. In passing from A to B, figs. 11 and 12, by the several lines c, d, e, f, we have the profiles shown at c, d, e, f, from which it appears, that the nearer we cross to the heads of streams, the less is the difference of heights.
Fig. 11.
Fig. 12.
Fig. 12 (a).
35. If we wish to go from A to B, fig. 12 (a), we should of course take first the straight line; but being obliged to avoid the hill C, on arriving at d, we should not try to recover that line at e, but proceed at once to B. Also as we are obliged to pass through d, we ought to go directly to d and not by the way of c; and the same idea is repeated between A and d; the last line being A b d B. Few rules can be given in the choice of routes. Practice only will enable the engineer to find the best location for a railroad.
36. The relative height of summits, the rate of fall of streams, and absolute elevation, within a few feet, may be easily, rapidly, and cheaply found by the barometer. This also affords an excellent check upon subsequent levelling operations. The results thus obtained depend upon the physical property, that the density of the air decreases as the square of the height.
37. The barometer is a glass tube, partly filled with mercury, having a vacuum in the upper part. By it the exact density of the air at any point is determined. Accompanying are two thermometers; one attached, showing the temperature of the barometer; the other detached, showing the atmospheric temperature.
38. Knowing now the manner of finding the density of the air at any two points, and also the relation between density and height, the operation of levelling by the barometer is very simple.
The modus operandi is as follows, (see tables A, B, C, and D):—
Let us have the notes.
| Barom. | Attached Therm. | Detached Therm. | |
|---|---|---|---|
| Upper Station, | 29.75 | 28.5 | 27.9 |
| Lower Station, | 26.80 | 36.8 | 36.3 |
| Latitude 46° N. | |||
| We have by table A, against the bar. point, | 29.75, | 6108.6 |
| also by table A, against the bar. point, | 26.80, | 5276.6 |
|
|
||
| The difference | 832.0 | |
| Diff. of attached therm. 36.8°- 28.5° = 8.3° | (table B) | -12.2 |
|
|
||
| 819.8 | ||
| Double the sum of detached thermometers multiplied by 1 1000 of 819.8 is |
||
| 2(27.9 + 36.3) × .8198 = | + 105.3 | |
|
|
||
| 925.1 | ||
| Correction (see table C) for lat. 46° N. and approximate height 925.1 | + 3.1 | |
|
|
||
| 928.2 | ||
Final correction by table D. The barometer at the lower station being 26.80, and the tabular number against 27.56 being 0.22, that for 26.80 will be 0.31, and we have
which add to 928.2 and we have as the final height
The tables above referred to, are those of Mr. Oltman, and are considered as the most convenient and reliable of any published.